Hammer



l. MARGOLIS HAMMER Filed oct. 2o, 1958 /N VEA/Tok [Sa n? zgajzff.

M YLML TORNE P5.

Patented Oct. 10, 1939 UNITED STATES PATENT OFFICE j 8 Claims.

This invention relates to power hammers.

The main objects of this invention are to provide an improved power hammer of high eiiiciency; to provide a hammer in which the force from the rotating power driven shaft is applied to the power head in a novel and more eicient manner; to provide a hammer having a hydraulic power transmitting unit interposed in its line of drive; to provide a hammer of simple construction which is rugged, sturdy, and capable of long usage without repair or adjustment; to provide a hammer which is adapted to a wide variety of uses, including the bumping out and working of sheet metal, particularly with respect to repair work on automobile fenders and the like; to provide a hammer in which well known principles of hydraulics are utilized to increase the power of the hammer head.

An illustrative embodiment of this invention is shown in the accompanying drawing, in which:

Fig. 1 is a view in longitudinal medial section of the improved hammer. j

Fig. 2 is an enlarged fragmentary plan View, with parts broken away, showing the driving cam and plunger actuated thereby.

Fig. 3 is an enlarged sectional view taken on the line 3 3 of Fig. 1, looking in the direction indicated by the arrows.

Fig. 4 is a view in elevation of one of the various forms of hammer heads which are adapted to be removably mounted in the improved hammer.

In the construction shown in the drawing, the improved hammer comprises an elongated semicylindrical body casing Ill having a cylindrical -handle portion I2 integrally cast therewith and extendingat right angles thereto, and a companion elongated semi-cylindrical body casing cover portion I4 which is complementary to the casing portion IU.

As shown most clearly in Fig. 3 of the drawing,

the casing portion I0, at diametrically opposite sides, is provided with integrally formed radially extending flanges I6 and I8, and the casing portion I4 is provided with like flanges 20 and 22. The flanges of 'the casing portions IU and I4 are provided with registering apertures therethrough, those in the flanges I6 and I6 being threaded to receive screws 24 by which the two casing halves are rigidly secured together at a plurality of spaced points, as shown in Fig. 2. A gasket 26 is preferably interposed between the flanges, as is customaryJ in assemblies of this character.

(Cl. 12S-33) The handle portion I2 is provided with a bushing 28 in which is journaled a driving shaft 30, one end of which is axially bored and tapped, as shown at 32, to receive the threaded end of a flexible driving cable 34 of any suitable character. 5 The other end of the driving shaft 30 extends into the body portion of the hammer and has a three lobed cam 36, non-rotatably secured thereon by a key 38. The adjacent end of the bushing 28 is radially anged, as shown at 40, and the cam l0 36 is held thereagainst by an adjusting screw 42 which is threaded through the body cover I4, and by the rotation of which a proper working clearance of the cam may be secured against the axial face of the flange 40. The inner end of the 15 screw 42 is conical and contacts the axial center of the shaft 30.

The cam 36 is located within a chambered space 44, cored or otherwise suitably formed within the body portion of the hammer, and a 20 suitable spring covered opening 46 is provided through which lubricant may be introduced to the cam chamber for lubricating the cam and its bearing surfaces.

The body portion of the hammer is provided 25 with axially spaced bearings 48 and 50 which may be in the form of separable halves, and which are prevented from rotating with respect thereto by radially extending diametrically positioned pins 52 and 54, respectively. The 30 bearings 48 and 50 journal an axially extending plunger 56, .one end of which is rounded, as shown at 58, and bears against the face of the\cam 36. The body of the hammer between the bearings 48 and 50 is also chambered out, as shown at 60, to 35 house a helical compression spring 62, one end of which bears against the end of the chamber adjacent the bearing 50, and the other end of which bears against an lannular collar 64 integrally formed on the plunger 56 for normally 40 constantly urging the rounded end 58 of the plunger into contact with the cam 36. The chamber 60 is also provided with a spring cover oil tting 66 through which lubricant may be introduced into the chamber 6U for the moving 45 parts therein.

The other end 68 of the plunger 56 has a relatively snug working fit in a. cylindrical bore 1U of a cylindrical sleeve or liner 12, so as to function as a piston. The cylinder 'I2 is also pro- 50 vided with a coaxial cylindrical bore 14, communicating with and of larger diameter than the bore 10, and is adapted to slidably receive a snugly fit piston head 16 in spaced relation to I the bore 10. The space. between the piston head 55 18 and the smaller diameter bore 18 is adapted to be lled with a liquid I8 which may be introduced thereto through a threaded aperture normally closed by a. screw 80. l

Corresponding apertures for the screw 80 in the body member I4 and the liner I2 are maintained in registry by a pin 82, one end of which extends into an opening in the liner, and the other end of which extends into a corresponding opening in the body portion I0.

The piston head 16 is integrally formed on one end of an axially extending shank 84 of smaller diameter than the bore 14 and is journaled in a bearing 86 which may be in the form of two halves and which is carried by the body members ID and i4 at the end thereof. Rotation of the bearing halves is prevented by pins 88 in the usual manner.

Means are provided for normally constantly urging the piston head 16 toward the cam driven plunger rod 56 to maintain the liquid 18 interposed therebetween under compression, and comprises a helical compression spring 9U, one end of which bears against the body casing members l and I2 closely adjacent the bearing 86, and the other end of which bears against an axial face of the piston head 16.

The outer end of the shank 84 protrudes beyond the bearing 86 and is axially bored and tapped to receive the threaded shank 52 of a hammer head 84. A plurality of hammer heads 94 having Ya .wide variety of shapes for performing various kinds of work may be provided for the hammer, such as round balls of various sizes, chisels, etc, One form of hammer head 96 adapted for riveting is shown in Fig. 4 of the drawing. This hammer head is circular in cross section, and the end face is provided with a concavity 88 for forming a convex head on a rivet.

In order to steady the hammer in use and permit its being held in both hands, a handle |00 is provided in alignment and at the rear end of the body, and which may be detachably secured thereto by relatively long screws |02, 184, and |06 which pass through arcuate shaped segments |88 and IIU extending from each end of the handle portion |00.

The bearings 48, U and 86, as well as the sleeve 28 are provided with oil grooves in the faces thereof, as is customary for lubrication, and the body portions l0 and I4 adjacent these bearings are drilled out, as shown at l l2 so that lubricant from the chamber 68 may readily pass to these bearings.

In the use of this hammer the driving shaft 30 is attached to a power driven flexible cable having any suitable source of power, such as an electric motor, or an air motor, or the like. Rotation of the shaft 30 will drive the cam 36 so as to give three impulses to the plunger 56 against the action of compression spring 62 for each rotation of the shaft 38. The spring 62 is of suiiicient strength to maintain the rounded end 58 of the plunger 56 in contact with the face of the three lobed cam 36, and thus reciprocate the plunger 56 axially within the body portion formed by the casing members Ill and I4.

Reciprocation of the plunger 56 to the left, as viewed in Fig. 1 of the drawing, due to the close fit of the plunger end 68 within the bore 10, drives the fluid therein out of the bore 18 into the enlarged bore 14. The difference between the diameter of these bores may be in the ratio of l to 11/2, or may be of any other suitable or desired ratio so as to secure the desired result. As is well understood, the difference in diameter governs the ratio of power stepup between the plunger 56 and the piston head 16, this increase being in direct proportion to the relative cross sectional areas of the bores l0 and 14. Reciproeating motion of the plunger 56 will reciprocate the fluid 18 in the bores 1U and 14, and thus reciprocate the piston head 16 and shank 84 integral therewith, to thus reciprocate the hammer head 94.

Any slight seepage of the liquid 18 around the piston head 16, or the close tting end 68 of the plunger 56, may be replenished by removal of the screw 80 and the introduction of more fluid while holding the piston head 16 to the left, as Viewed in Fig. 1 of the drawing with the spring 90 compressed. As soon as relling operation is finished and the screw 80 replaced, the shank 84 may be released, thus permitting the spring 8U to again maintain the liquid 18 under compression.

Although but one specic embodiment of this invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of this invention, as defined by the following claims.

What is claimed is:

1. A hammer comprising a body portion, a cam rotatable in said body portion, an axially reciproeable plunger having one end in Contact with said cam, a spring acting on said plunger for maintaining said plunger in constant contact with said cam, a cylinder having a bore therein for receiving the other end of said plunger, said cylinder having another communicating bore of larger diameter than said first mentioned bore, a

piston slidable in said larger cylinderbore, a hammer head secured to said piston, and a liquid in saidbore interposed between said piston and plunger and for imparting motion from said plunger to said piston.

2. A structure as dened in claim l in which a helical compression spring acts on said piston for maintaining said liquid under pressure at all times.

3. A hammer comprising a semi-cylindrical body easing, a cylindrieal handle portion integrally formed therewith and extending transversely with respect thereto', a semi-cylindrical body member complementary to said rst mentioned body member, each of said body members being provided with oppositely extending substantially diametrieally aligned flanges, means for securing said anges together to form a substantially cylindrical hammer body, a drive shaft journaled in said handle portion, a cam rigidly mounted on said drive shaft within said body portion, a plunger axiallyreciprocable within said body with one end thereof in position to be actuated by said cam, yielding means for maintaining said plunger end in substantially constant contact with said cam, a cylinder having a bore therein for receiving the other end of said plunger, said cylinder having a second bore therein of greater diameter than said rst mentioned bore and communieating therewith, a piston slidably mounted within said larger cylinder bore, yielding means normally urging said piston toward the adjacent end of said plunger, liquid within said cylinder bores interposed between said piston and plunger end, and a hammer head secured to said piston.

4. In a power hammer, a body portion, a plunger axially reeiprocable within said body portion, a power driven cam for actuating said plunger, a second plunger normally in spaced relation with respect thereto, and a liquid sealed between Asaid plungers for transmittingmotion from one of said plungers to the other of saidv plungers.

5. A power hammer as characterized in claim 4 in which each of said plungers is provided with a helical compression spring for normally urging said plungers in one direction.

6. A hammer comprising a body portion, a cam rotatable in said body portion, an axially reciprocable plunger having one end in contact with said cam, a spring acting on said plunger for maintaining said plunger in constant contact with said cam, a cylinder having a bore therein for receiving the other end of said plunger, a second cylinder having a bore therein communicating with said first cylinder bore, a piston slidable in said second cylinder bore, a hammer head secured to said piston, and a liquid in said bores interposed between said piston and plunger for imparting motion from said plunger to said piston.

7. A structure as defined in claim 6 in which a helical compression spring acts on said piston for maintaining said liquid under pressure at all times.

8. A hammer comprising a semi-cylindrical body casing, a cylindrical handle portion integrally formed therewith and extending trans- Versely with respect thereto, a semi-cylindrical body member complementary to said first mentioned body member, each of said body membersv being provided with oppositely extending substantially diametrically aligned flanges, means for securing said flanges together to form a substantially cylindrical hammer body, a drive shaft journaled in said handle portion, a cam rigidly mounted on said drive shaft within said body portion, a plunger axially reciprocable Within said body with one end thereof in position to be actuated by said cam, yielding means for maintaining saidplunger end in substantially constant contact with said cam, a cylinder having a bore therein for receiving the other end of said plunger, the second cylinder having a bore therein communicating with said rst cylinder bore, a piston slidably mounted in said second cylinder bore, yielding means normally urging said piston toward the adjacent end of said plunger, liquid within said cylinder bores interposed between said piston and plunger end for imparting motion from said plunger to said piston, and a hammer head secured to said piston.

ISADORE MARGOLIS. 

